During a leak test, which condition is required?

• A. Some pressure loss allowed
• B. Zero pressure loss in 1 minute
• C. Gauge must move
• D. No movement allowed

Answer: (B)

When testing for leaks, the goal is to confirm the system can hold the charged pressure without losing it. The best criterion is that there is zero pressure loss in the specified interval (one minute). Holding the pressure steady shows all joints, fittings, and seals are retaining the test pressure and that there are no leaks. Any drop indicates a leak or faulty seal that must be fixed before the system is considered ready. If you allowed some pressure loss, even small leaks could go undetected; saying the gauge must move describes a changing pressure rather than confirming integrity, and saying no movement is ambiguous. The key idea is to maintain the tested pressure with no detectable drop for the full minute.